MOCVD reactors that utilize vertical flow, high speed horizontally rotating substrates are known in the art. However, known types of such conventional reactors exhibit several significant disadvantages. One disadvantage relates to an inability to readily employ ultraviolet (UV) radiation for laser-assisted growth and in-situ etching. Another disadvantage relates to a large mercury consumption and to a required heating of the reactor walls due to a requirement that the entire reactor volume be filled with a desired partial pressure of mercury. Another disadvantage is related to a non-optimum mercury injection flow dynamic. In that CVD and in particular MOCVD are important fabrication methodologies for producing high quality semiconductor materials containing Hg, such as Group II-VI semiconductor devices comprised of mercury-cadmium-telluride (HgCdTe), overcoming the deficiencies of the conventional vertical flow, horizontally rotating substrate reactor is an important goal.
It is thus one object of the invention to provide a CVD reactor having a horizontally rotating substrate support that employs laser radiation to achieve relatively low temperature growth and laser-stimulated in-situ etching.
It is another object of the invention to provide a horizontally rotating CVD reactor that does not require that the entire reactor volume be filled with Hg in order to maintain a desired pressure of Hg in the growth zone, thereby reducing Hg consumption and avoiding a requirement of heating the reactor walls.
It is a further object of the invention to provide a horizontally rotating CVD reactor that exhibits an intrinsically stable gas flow dynamic due to an optimum injection of Hg into the reactor.
It is a further object of the invention to provide Hg injection in a manner that avoids contact with stainless steel, thereby eliminating possible contamination of the Hg and the grown semiconductor layers.
It is a still further object of the invention to avoid gas-phase interactions between reactive species created by laser photodissociation by restricting the illuminated volume to a thin region adjacent to the substrate, the illuminated volume being preferably less than one mean free path in thickness.